Needle assembly for drug pump

ABSTRACT

An apparatus ( 110 ) includes an activation mechanism ( 20 ) and a safety latch ( 122 ). The activation mechanism is operative to deploy a needle ( 116 ) to protrude out of a housing ( 112 ), the needle ( 116 ) having a longitudinal axis. The safety latch ( 122 ) is movably mounted on the housing ( 112 ) and formed with a needle opening ( 129 ) to allow the needle ( 116 ) to pass therethrough. The safety latch ( 122 ) has a first position wherein the needle ( 116 ) is aligned to pass through the needle opening ( 129 ) and a second position wherein the safety latch ( 122 ) is moved with respect to the housing ( 112 ) such that the needle ( 116 ) is blocked from movement in a direction parallel to the longitudinal axis thereof by a portion of the safety latch ( 122 ) distanced from the needle opening ( 129 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 14/553,399, filed Nov. 25, 2014, which is a continuation of U.S. patent application Ser. No. 14/258,661, filed Apr. 22, 2014, now U.S. Pat. No. 9,149,575, which is a continuation of U.S. patent application Ser. No. 13/521,167, filed Jul. 9, 2012, now U.S. Pat. No. 8,915,882, which is a section 371 of International Application No. PCT/US2011/021604, filed Jan. 19, 2011, which was published in the English language on Jul. 28, 2011 under International Publication No. WO 2011/090955, which is a continuation-in-part of U.S. patent application Ser. No. 12/689,249, filed Jan. 19, 2010, now U.S. Pat. No. 8,348,898, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention generally relates to external drug pumps, and particularly to a needle assembly for a drug pump, particularly suitable for elderly, invalid or physically challenged persons.

External drug pumps are typically used to deliver to patients substances which contain large molecules which cannot be digested when administered orally, such as insulin. Typically, the pump is adhered to the abdomen of the patient and delivers the substance to the patient via a cannula or needle that is inserted into the patient's skin.

U.S. patent application Ser. No. 12/345,818 filed Dec. 30, 2008, and PCT Patent Application PCT/US09/69552, filed Dec. 27, 2009, to the same inventor, describe a needle assembly for administering a drug from a vial. (The terms “drug” and “substance” are used interchangeably throughout the specification and claims, and encompass any material administered to a subject. The term “cartridge” throughout the specification and claims encompasses any container for a drug, such as but not limited to, a cartridge, vial, syringe, bottle, ampoule and many more, and is not limited to any size or shape.) The needle assembly includes a needle held in a needle holder, and an activation mechanism for activating delivery of the substance through the needle, such as a push button that initiates the delivery of the substance. The activation mechanism includes a safety latch that prevents the needle from pricking a person accidentally and prevents inadvertent administration of the drug. The safety latch initially impedes movement of the needle holder. When the safety latch is placed on the subject, the safety latch moves to a position that permits moving the needle holder to cause the needle to protrude outwards of the housing to pierce the subject to allow administration of the substance to the subject.

A problem of this prior art needle assembly is that elderly, invalid or physically challenged persons may find it difficult to push the push button to activate delivery of the substance.

BRIEF SUMMARY OF THE INVENTION

In accordance with an aspect of the invention, there is provided an apparatus comprising an activation mechanism and a safety latch. The activation mechanism is operative to deploy a needle to protrude out of a housing, said needle having a longitudinal axis. The safety latch is movably mounted on said housing and formed with a needle opening to allow said needle to pass therethrough. The safety latch has a first position wherein said needle is aligned to pass through said needle opening and a second position wherein said safety latch is moved with respect to said housing such that said needle is blocked from movement in a direction parallel to the longitudinal axis thereof by a portion of said safety latch distanced from said needle opening.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which:

FIG. 1 is a simplified illustration of apparatus for administering a substance to a subject, from the prior art (U.S. patent application Ser. No. 12/345,818 or PCT Patent Application PCT/US09/69552);

FIG. 2 is a simplified illustration of a safety latch of the prior art apparatus in the down position, this being the nominal (starting) position as long as the apparatus has not yet been placed upon the user's body, and a needle holder cannot be pushed down;

FIG. 3 is a simplified illustration of the prior art safety latch in the up position, which is the position when the apparatus has been placed upon the user's skin;

FIG. 4 is a simplified illustration of lifting the prior art apparatus off the patient's body after finishing the drug administration, which causes the safety latch to move back to the down position;

FIG. 5 is a simplified illustration of the prior art needle holder moving back up and getting stopped in the up position with the needle retracted back into the housing of the apparatus;

FIG. 6 is a simplified illustration of biasing device release apparatus used in administering a substance to a subject, constructed and operative in accordance with an embodiment of the present invention;

FIG. 7 is a simplified illustration of a safety latch of the biasing device release apparatus of FIG. 6 in the up position, which is the position when the apparatus has been placed upon the user's skin;

FIG. 8 is a simplified illustration of an actuator moving a biasing device arrestor out of a housing so as not to block a biasing device which can urge a needle of the apparatus to pierce a patient's skin, in accordance with an embodiment of the present invention;

FIG. 9 is a simplified illustration of the biasing device urging the needle to a piercing position, in accordance with an embodiment of the present invention; and

FIG. 10 is a simplified illustration of the biasing device release apparatus lifted off the patient's body after finishing the drug administration, which causes the safety latch to move back to the down position and the needle to be retracted back into the housing.

FIGS. 11A and 11B are simplified perspective illustrations of the biasing device release apparatus employed in another apparatus (drug pump) for administering a substance to a subject, constructed and operative in accordance with an embodiment of the present invention;

FIG. 12 is a simplified illustration of the inside of the apparatus in the position of FIGS. 11A-11B

FIGS. 13A and 13B are simplified perspective illustrations of the apparatus of FIGS. 11A-11B, in a second stage, after application of the apparatus on the patient's body, in accordance with an embodiment of the present invention;

FIG. 14 is a simplified illustration of the inside of the apparatus in the position of FIGS. 13A-13B;

FIG. 15 is a simplified perspective illustration of the apparatus of FIGS. 11A-11B, in a third stage, in which the needle protrudes out of the pump and is inserted in the body, in accordance with an embodiment of the present invention;

FIG. 16 is a simplified illustration of the inside of the apparatus in the position of FIG. 15;

FIGS. 17 A and 17B are simplified perspective illustrations of the apparatus of FIGS. 11A-11B, in a fourth and final stage, after removing the apparatus from the patient's body, in which a protector blocks the needle after use, in accordance with an embodiment of the present invention; and

FIG. 18 is a simplified illustration of the inside of the apparatus in the position of FIGS. 17A-17B.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to FIG. 1, which illustrates apparatus 10 for administering a substance, for example, insulin, to a subject, from the prior art (U.S. patent application Ser. No. 12/345,818 or PCT Patent Application PCT/US09/69552.

A cartridge 12 (also referred to as a vial, the terms being used interchangeably) is mounted on a housing base 14. For some applications, a cartridge piercing mechanism 18 is movably (e.g., rotatably) coupled to housing base 14 and pierces the distal end of cartridge 12. The substance to be administered flows from cartridge 12 to an activation mechanism 20 via a tube (not shown). The activation mechanism 20 has a control button 22 and is typically coupled to the housing base 14. The activation mechanism 20 is configured to insert a cannula and/or a needle through the subject's skin and to deliver the substance via the cannula and/or the needle. The embodiments of the invention are described with reference to a needle alone, but apply as well to a needle disposed in a cannula or any other delivery device. The term “needle” is used throughout the specification and claims to encompass all such delivery devices.

Apparatus 10 typically includes a motor, a battery and a control unit (all not shown). After the needle has penetrated the skin of the patient, the control unit controls operation of the motor to administer a controlled amount of the substance to the patient at a controlled rate of delivery. Of course, the needle assembly of the present invention can be used in other applications and does not have to be used with a controlled motorized delivery system.

Reference is now made to FIGS. 2 and 3, which illustrate a safety latch of the prior art. Control button 22 has a shaft 24 which is arranged to move (vertically downwards in the sense of the drawings) against a needle holder 26 (FIG. 3) which holds a needle 28. The shaft 24 and the needle holder 26 are both confined to move in a (e.g., tubular) housing 30, but there is a difference in their movements. Shaft 24 is confined to translate downwards in housing 30 with no rotation. In contrast, needle holder 26 can not only translate but can also rotate in housing 30, as will be explained more in detail below.

The movement of needle holder 26 is selectively impeded by a safety latch 32, which is pivotally mounted on housing base 14 about a pivot 34. Safety latch 32 is arranged to selectively pivot in and out of a complimentary shaped groove 37 (FIG. 1) formed in housing base 14. Safety latch 32 includes a first arrestor 36 at a distal end thereof and a second arrestor 38 proximal to and spaced from the first arrestor 36. The arrestors may be shaped as lugs or other projections or any other structure suitable for arresting motion of needle holder 26 as will be explained below.

FIG. 2 shows safety latch 32 in the down position, which is its nominal (starting) position as long as apparatus 10 has not yet been placed upon the user's body. In this position, first arrestor 36 abuts against an ear 40 that projects from a bottom portion of needle holder 26. It is noted that pushing ear 40 down against a surface 42 of first arrestor 36 will not cause downward movement of needle holder 26 because this will simply pivot first arrestor 36 about the pivot 34 causing another surface 44 of first arrestor 36 to abut against the bottom surface of housing 30. Thus, when safety latch 32 is in the down position, needle holder cannot be pushed down (in the sense of the drawing of course).

FIG. 3 shows safety latch 32 in the up position (that is, it has pivoted upwards about pivot 34), which is the position when apparatus 10 has been placed upon the user's skin. First arrestor 36 has been moved out of the way of ear 40 of needle holder 26, so that control button 22 can now be pressed down to move needle holder 26 downward, thereby piercing the patient's skin. Needle 28 remains inserted in the patient for the duration of the drug administration. Pressing control button 22 down causes shaft 24 to become locked in the down position in housing 30, such as by means of one or more splines (not shown here), which radially project outwards from shaft 24, sliding past one or more chamfered resilient tongues (not shown here) mounted in housing 30. After the splines slide past tongues, the splines become locked in place by the action of the tongues resiliently snapping back in place over them.

After finishing the drug administration, apparatus 10 is lifted off the patient's body. This causes safety latch 32 to move back to the down position as shown in FIG. 4, thereby moving second arrestor 38 away from ear 40. A biasing device 47, such as a leaf spring biased between first arrestor 36 and housing base 14, may be employed to impart a returning force on safety latch 32 to move it back to the down position. A slanted tongue 50 applies a downward force on ramp 52, thereby permitting needle holder 26 to rotate counterclockwise until slanted tongue 50 slides off ramp 52. At this point, needle holder 26 jumps back up and ear 40 gets caught on a shoulder 54 formed on housing 30 as shown in FIG. 5. In this position, needle bolder 26 cannot move back down because of ear 40 being arrested against shoulder 54. Accordingly, needle 28 is trapped back inside apparatus 10 in a safe position, and apparatus 10 may be safely discarded.

Reference is now made to FIG. 6, which illustrates biasing device release apparatus 60 for administering a substance to a subject, constructed and operative in accordance with an embodiment of the present invention. Elements of the present invention which are identical or equivalent to elements described above for the prior art are designated with the same reference numerals.

As previously described, in the prior art apparatus, after drug administration, needle bolder 26 retracts back into housing 30 by the action of counterclockwise rotation and ear 40 getting caught on shoulder 54 formed on housing 30. In the present invention, this same arrangement can be used. Alternatively or additionally, a biasing device 59, such as a coil spring, can be used to retract needle holder 26 back into housing 30 after drug administration. Biasing device 59 is arranged to apply an urging force on needle 28 in the direction of arrow 57 (upwards in the sense of the drawings).

With biasing device release apparatus 60, the user does not have to apply a force for the mechanical operation of the device. Rather either there is no control button to push down, or alternatively the control button can be touch sensitive or be operated on slight pressure, and a biasing device 70, such as a coil spring, is released to push down needle 28, as described below. Biasing device 70 is stronger than biasing device 59. Biasing device 70 is arranged to apply an urging force on needle 28 in the direction of arrow 71 (downwards in the sense of the drawings).

Apparatus 60 includes a biasing device arrestor 62, such as a tongue or dog mounted on a shaft 63, and enters housing 30 through an aperture 64. An actuator 66 is provided for moving biasing device arrestor 62. For example, actuator 66 may be, without limitation, a step motor, linear actuator, solenoid and the like. In the non-limiting illustrated embodiment, actuator 66 is a step motor that rotates a drive gear 68 that meshes with a spur gear 72 mounted on shaft 63. Biasing device arrestor 62 may be threadedly mounted on a threaded portion 74 of shaft 63.

A safety latch position sensor 76 is provided for sensing when safety latch 32 moves to the up position of FIG. 7. Safety latch position sensor 76 may be, without limitation, a reed switch or any other kind of switch or sensor suitable for sensing the movement of safety latch 32 to the up position. Safety latch position sensor 76 is in communication with a controller 78, which controls operation of actuator 66. As mentioned above, the prior art apparatus 10 typically includes a motor, a battery and a control unit. Actuator 66 can be this same motor and controller 78 may be this same control unit, or they may be separate units.

FIG. 6 shows safety latch 32 in the down position, which is its nominal (starting) position as long as the drug administering apparatus has not yet been placed upon the 25 user's body, corresponding to FIG. 2 of the prior art. As described above, in this position, needle holder 26 cannot be pushed down (in the sense of the drawing). In the present invention, in this position, biasing device arrestor 62 is inside housing 30 and blocks biasing device 70, preventing it from pushing down on needle 28.

FIG. 7 shows safety latch 32 in the up position (corresponding to FIG. 3 of the prior art), which is the position when the drug administering apparatus has been placed upon the user's skin. Safety latch position sensor 76 senses the movement of safety latch 32 to the up position and signals controller 78 that safety latch 32 is now in the up position. Controller 78 thereupon commences operation of actuator 66. In a preferred embodiment, controller 78 initiates operation of actuator 66 after a predetermined time delay (e.g., 5-15 seconds) to ensure that the drug administration apparatus was indeed placed on purpose on the patient for administering the drug.

When operated, actuator 66 moves biasing device arrestor 62 out of aperture 64, as shown in FIG. 8. In the non-limiting illustrated embodiment, actuator 66 rotates drive gear 68, which in turn rotates spur gear 72 to rotate shaft 63. Rotation of shaft 63 causes biasing device arrestor 62 to move linearly out of aperture 64 along threaded portion 74. When biasing device arrestor 62 reaches the end of threaded portion 74, it rotates freely on shaft 63 and moves no further.

As soon as biasing device arrestor 62 has moved out of aperture 64, biasing device 70 is no longer blocked and it now pushes down on needle 28 (overcoming the weaker biasing device 59), as shown in FIG. 9. Needle 28 now piercing the patient's skin and administers the drug. As described for the prior art apparatus, shaft 24 becomes locked in the down position in housing 30.

After finishing the drug administration, the apparatus is lifted off the patient's body. As described for the prior art apparatus, this causes safety latch 32 to move back to the down position as shown in FIG. 10, and needle 28 is trapped back inside the apparatus in a safe position, and the apparatus may be safely discarded.

Reference is made to FIGS. 11A-11B and 12, which illustrate the biasing device release apparatus 60 employed in another apparatus 110 (also referred to as drug pump 110) for administering a substance to a subject, constructed and operative in accordance with an embodiment of the present invention. Elements of biasing device release apparatus 60 are designated with the same reference numerals as above.

The activation mechanism 20 is also employed in this embodiment. However, as opposed to the previously described embodiments, in apparatus 110, the needle is not retracted back into the housing after drug administration, but there is a protector that blocks the needle after use for preventing accidental needle pricks, as is described more in detail hereinbelow.

In apparatus 110, the cartridge (not shown) is mounted on a housing base 112 (or simply housing 112), as shown in FIGS. 11A-11B. A hollow needle (not shown) is provided in housing 112 for piercing a septum at a distal end of the cartridge. The substance to be administered flows from the cartridge eventually to a needle 116 held in a needle holder 118 (confined to move in a housing 117), as controlled by biasing device release apparatus 60. As described above, with biasing device release apparatus 60, there is no control button to push down. Instead biasing device 70 is released to push clown needle 116, in the same manner as described above.

The movement of needle holder 118 is selectively impeded by a safety latch 122, which is pivotally mounted on housing base 112 about a pivot 124. Safety latch 122 is arranged to selectively pivot in and out of a complimentary shaped groove 126 formed in housing base 112. Safety latch 122 may be biased by a biasing device 128, such as a coil spring. Safety latch 122 is formed with a needle opening 129 to allow needle 116 to pass therethrough.

In the first stage shown in FIGS. 11A, 11B and 12, before operation, safety latch 122 blocks the path of needle 116 for preventing against inadvertent, premature activation (the blocking mechanism as described, for example, in U.S. patent application Ser. No. 12/345,818 or PCT Patent Application PCT/US09/69552).

A microsensor 120, such as a photo-microsensor, may be provided for sensing the position of the needle for use in conjunction with the control unit to control the various stages of the operation of the pump. In addition to the photo-microsensor 120, another sensor 130 (FIG. 12) may be provided for sensing the position and operation of safety latch 122. For example, sensor 130 may be a magnet sensor 130 that senses if a magnet 132 mounted on the distal end of safety latch 122 is near sensor 130 or not.

In the second stage shown in FIGS. 13A, 13B and 14, apparatus 110 is placed on the patient's body (not shown), and safety latch 122 has pivoted to be flush with housing base 112. Needle 116 is now aligned to be advanced through needle opening 129 of safety latch 122. An indication may be provided that pump 110 is on the body by magnet sensor 130 sensing the magnet 132 on safety latch 122 (or any other suitable sensing mechanism). (It is noted that biasing device release apparatus 60 is not shown in FIG. 14 for the sake of simplicity.)

As described above, biasing device 70 of biasing device release apparatus 60 is then released to push down needle 116 into the patient's body, in the same manner as described above. Needle 116 advances through needle opening 129 of safety latch 122 to the position shown in FIGS. 15 and 16 (third stage of operation). The sensing mechanism may provide an indication indicating that the needle 116 is inserted. Needle 116 stays locked in the insertion position.

Reference is made to FIGS. 17A, 17B and 18. In the fourth and final stage of operation, after administrating the substance, pump 110 is removed from the patient's body, thereby releasing safety latch 122 to pivot to the down position. However, since needle 116 is already protruding out of the housing and remains locked in the protruded position, needle 116 does not align with needle opening 129 of safety latch 122, as seen best in FIG. 18. Thus, safety latch 122 serves as a protector that blocks the tip of needle 116 after use of pump 110 for preventing accidental needle pricks.

It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art. 

We claim:
 1. A drug delivery device for administering a medicament to a patient comprising: a housing having an injection needle therein; a needle insertion apparatus for ejecting at least a tip of the injection needle out of the housing; a safety latch coupled to the housing, the latch being movable from a first position prior to use of the drug delivery device to a second position when the drug delivery device is placed on the patient; a safety latch position sensor configured to detect at least the second position of the safety latch; and an electronic controller electronically coupled with the safety latch position sensor and configured to control operation of the needle insertion apparatus; wherein with the housing in contact with the patient, and the safety latch in the second position, the safety latch position sensor electrically signals the electronic controller, which, in turn, initiates operation of the needle insertion apparatus.
 2. The drug delivery device of claim 1, wherein the needle insertion apparatus comprises a biasing device, biased to eject the injection needle, a biasing device arrestor blocking movement of the biasing device, and an actuator coupled with the biasing device arrestor and operatively controlled by the electronic controller, wherein the electronic controller initiates the operation of the actuator when the safety latch is in the second position, which withdraws the biasing device arrestor from blocking movement of the biasing device, and, in turn, permitting the biasing device to eject the injection needle.
 3. The drug delivery device of claim 2, wherein the electronic controller is configured to initiate the operation of the actuator after a predetermined time delay from receiving the signal from the safety latch position sensor that the safety latch is in the second position.
 4. The drug delivery device of claim 3, wherein the predetermined time delay ranges between 5 seconds to 15 seconds.
 5. The drug delivery device of claim 1, wherein the safety latch position sensor is a reed switch. 